TEN months after the outbreak of the Ebola virus disease (EVD) began in Guinea in West Africa in December 2013 ( Frontline , September 19), the disease still persists, and Guinea, along with Liberia and Sierra Leone, is among the worst-affected countries. The numbers of reported EVD cases in these countries have been growing from week to week, and as of November 2, the total number of cases (including confirmed, probable and suspected) reported by these countries is 13,015, which include 4,808 deaths (see table and chart). These numbers exceed the combined numbers of all previous Ebola outbreaks.
According to the World Health Organisation’s (WHO) “Ebola Response Roadmap Situation Report” of November 5, at the country level the weekly incidence of the disease appears to be stable in Guinea, while it seems to be declining in Liberia and is on the rise in Sierra Leone. In these three countries, Ebola virus transmission is persistent and widespread and even though the weekly trends may show varying trajectories, the transmission continues to be intense. Also, as the WHO clearly states in its report, cases and deaths continue to be underestimated owing to instances of symptomatic persons evading diagnosis and treatment, inaccurate recording in the national databases of diagnosed cases, and persons with suspected EVD being buried without proper diagnosis.
There was, in fact, a spurt in the number of cases in the last week of October, the reason for which is not clear. While Guinea reported 93 new confirmed cases in that week, Liberia reported 444 cases (most of them likely to be confirmed EVD cases) and Sierra Leone 325 confirmed cases. Liberia remains the worst affected, with all but one of its 15 counties having reported one confirmed or probable case. The transmission of the virus continues to be the most intense in the capital cities of the three countries, Conakry, Monrovia and Freetown, with the number of cases during the week being 50, 305 and 138 respectively. Recently, Robert Snyder and others from the University of California-Berkeley, commenting in Lancet, drew attention to how the large and growing urban slum populations in these capitals, with their poor sanitation, poverty and inadequate health access, remain flashpoints in this outbreak and called it the “elephant in the room”.
Besides these three countries, the West African epidemic has spread to Nigeria, Senegal and Mali. While Nigeria reported its first case in mid-July, Senegal reported its first case in late August. Mali is the last to be sucked into it, with its first case showing up on October 23. Other countries showing localised transmission are the United States and Spain, resulting from cases imported from one of the three countries with widespread and intense transmission (see chart).
In Nigeria, there have been 20 cases and eight deaths. In Senegal, there has been one case reported and no deaths. However, both Senegal and Nigeria have succeeded in containing and interrupting the transmission with effective disease management in patients and control measures. As a result, the WHO declared the outbreaks in Senegal and Nigeria to be over, on October 17 and 19 respectively.
The WHO has, in fact, held out these countries as models to be followed by other countries with relatively poor health infrastructure that have not been affected so far, especially those 15 in the neighbourhood of the major three, but that face a distinct threat of the infection spreading to them. Mali’s first reported case was a two-year-old girl who travelled with her grandmother from Guinea to Kayes in Western Mali, which is close to the border with Senegal. On October 22, she was admitted to a hospital where she died two days later. At present, 43 contacts, of whom 10 are health-care workers (HCWs), are being monitored and efforts to trace other contacts are on. A WHO team is in Mali to assess the country’s readiness, and a rapid-response team will be reaching there soon.
Outside Africa In October, a Spanish nurse tested positive for EVD; she had cared for two patients who had been sent to Spain for treatment from Liberia and Sierra Leone. This was the first confirmed case of Ebola transmission outside Africa. On October 19, the nurse tested negative for EVD and this was confirmed again on October 21. Spain will be declared Ebola-free if no new cases are reported 42 days after October 21. A total of 83 contacts linked to this case are being monitored.
The first case in the U.S. was reported on September 30, a person who had got infected in Liberia and returned to Texas. He died on October 8. Four cases and one death have been reported so far by the U.S. The most recent case is that of a Medecins Sans Frontieres (MSF) doctor who returned to New York from Guinea on October 17 and was diagnosed positive for EVD on October 23. The other two HCWs who contracted the infection while treating the first case have now tested negative for EVD.
A total of 172 contacts linked to these cases are being monitored, of which 60 have completed the 21-day monitoring period. The crew and passengers numbering 152 who were on the flight with the MSF worker, who was then asymptomatic, are also being monitored though they are considered low-risk. Despite advice to the contrary from the WHO and the United Nations, many countries, including the U.S., have imposed travel restrictions on people travelling to and from the affected countries. Some States in the U.S. have ordered HCWs and others returning from West Africa to be placed under a 21-day quarantine even though the guidelines of the Centres for Disease Control and Prevention (CDC) recommend only a 21-day mandatory monitoring of such people. Quarantining of HCWs has particularly caused widespread concern and condemnation.
As of October 19, a total of 443 HCWs have been infected; 244 of them have died. The WHO has stated that it is undertaking extensive investigations to determine the cause of infection in each case. Early indications, the WHO says, are that a substantial proportion of infections occurred outside the setting of health care and treatment. Checks on infection control and quality assurance in each treatment unit in the three countries are currently under way even as efforts are on to increase the supply of optimal personal protective equipment (PPE) to ensure that all HCWs are exposed to the minimum possible level.
Unrelated to the outbreak that originated in Guinea is another Ebola outbreak in the Democratic Republic Congo (DRC; formerly Zaire), which began in August. According to the WHO, the virus is the Zaire species, which is indigenous to the country, and the current one is closely related to a virus from the 1995 outbreak in the DRC. The outbreak is located in a remote district of the north-western part of the country, and results from genetic analysis of the virus, together with findings from the epidemiological investigation, are definitive.
“The outbreak in DRC is a distinct and independent event, with no relationship to the outbreak in West Africa,” the WHO has said. The introduction of the virus into the human population is stated to be following contact with infected bushmeat (usually fruit bats or monkeys). As of October 20, 66 cases (38 confirmed and 28 probable) have been reported, of which eight are HCWs. The government has rapidly mounted a robust response since the outbreak, and of the 1,121 contacts linked to the cases, 1,116 are said to have completed the 21-day follow-up.
Grim situation But the situation with regard to the main epidemic, which the WHO declared on August 8 as a “public health emergency of international concern”, is grim. “Liberia is facing a serious threat to its national existence,” said the country’s Defence Minister Brownie Samukai early last month. Without any speedy solution to the massive crisis, which is only showing signs of aggravating beyond their respective capacities, there is visible panic in the three governments that have ended up taking up some authoritarian and undesirable steps such as lockdowns and mass quarantines.
Indicators on the way the epidemic is likely to grow, in terms of spread of infection and growth projection, are provided by the WHO Ebola Response Team in a timely paper of October 16 in The New England Journal of Medicine . The analysis is based on outbreak data as of September 14 (4,507 cases, including 2,296 deaths) and the findings are a cause for global concern and demand enhanced international attention and action.
Since the virus is spread through contact with body fluids of symptomatic patients, transmission can be stopped by a combination of early diagnosis, contact tracing, patient isolation and care, infection control and safe burial. But, the paper said: “The epidemic has become so large that the three most-affected countries… face enormous challenges in implementing control measures at the scale required to stop transmission and to provide clinical care for all persons with EVD.” The critical factor for the epidemic size “appears to be the speed of implementation of rigorous control measures”, the team has said.
WHO analysis The WHO analysis has found that the majority of patients are 15 to 44 years of age. The team estimates the case fatality rate (CFR) to be 70.8 per cent among persons with known clinical symptoms of infection (the highest is for Liberia, at 72.3 per cent). In comparison, the naïve fatality rate as the ratio of reported deaths to reported cases (which include cases for which clinical outcomes are known) is found to be only 37.7 per cent. It is the inordinate delay between the onset of symptoms and clinical outcome that results in such an underestimate for CFR in different reports on the epidemic. The (correct) CFR is less for all hospitalised cases with definitive outcome at 64.3 per cent; this indicates that hospitalisation increases the chances of survival. Also, significantly, the CFR was lower for cases between August 18 and September 14 compared with that based on data up to August 18, which indicates better implementation of measures than earlier. But, obviously, this is happening quite late in the epidemic.
The other figure of importance is the reproduction number (R), which is the average number of persons that an infected person introduced into an uninfected population will potentially infect. The parameter reflects the maximum potential for growth in case incidence. When this indicator is greater than 1, the infection will continue to spread, and the greater the R, the higher the spread. The current value of R is 1.81 for Guinea, 1.51 for Liberia and 1.38 for Sierra Leone. This may be compared with the R values the initial period of exponential growth, which were 1.71, 1.83 and 2.02 respectively. The fact that R remains high even four or five months after that initial phase is worrisome indeed. Interestingly, according to the paper, between March and July, R for Guinea fluctuated around the threshold value of 1 but increased again in August, essentially because of the increase in case incidence in Macenta district. Between June and August, the value dropped in Sierra Leone. In Liberia, R has remained consistently high, reflecting the constant increase in the number of cases.
The paper estimates some key time periods as well. The mean incubation period was found to be 11.4 days, and the value did not vary much between the three countries. About 97 per cent of the cases had onset of symptoms within 21 days of exposure, which is the stipulated time for following up on contacts. The average time from onset of symptoms to hospitalisation was about five days, which means that because of lack of adequate hospital infrastructure or because of the negligent health-seeking behaviour of local populations, the infectiousness remains in the community. The mean length of stay in the hospital was 6.4 days. As the case numbers keep increasing, thousands of new beds will be required by the end of the year and the question that has to be asked is, where will these come from?
On the basis of data up to September 14, the paper estimates the doubling time with the above R values to be 15.7 days for Guinea, 23.6 days for Liberia and 30.2 days for Sierra Leone. Without any change in the control efforts between August and the present, the team estimated the number of cases to exceed 20,000 by November 2 (Guinea 5,740, Liberia 9,890 and Sierra Leone 5,000). Mercifully, the numbers (see table) have not hit those high levels, which is indicative of improved control efforts but a situation still far from the state of interruption of the virus transmission and an early end to the epidemic.
In September, the CDC too released a model which projects into the next year on the basis of which it is estimated that, in the worst-case scenario, up to 1.4 million people could be infected by the end of January. The model projects a figure of 550,000 cases in Liberia and Sierra Leone by January 20, but if under-reporting is to the extent of 60 per cent, the number becomes 1.4 million in these two countries. Guinea is not included in these projections because of wild fluctuations in case numbers there, according to the CDC. Such scary projections notwithstanding, international support and action, both in terms of money and material, has been inexplicably slow in coming. The international community has been late in realising and catching up with the enormity of the epidemic and the consequent challenges in controlling it.
International response MSF and the co-discoverer of the virus, Peter Piot, have called for a military response to the coordination of supplies and the building of treatment units, and for U.N. Peacekeeping Forces to be deployed. But, as Zoe Mullan, Editor of The Lancet Global Health, wrote a month back, this may not be the right solution. “The imagery,” she wrote, “conjured up by foreigners in biohazard suits or army camouflage can be powerfully negative, and even associated with the bringing of disease, rather than its banishment, as happened with cholera in Haiti.”
On October 4, a group of European medical researchers wrote an open letter to European governments. “After months of inaction and neglect from the international community, the Ebola epidemic in West Africa has now spiralled utterly out of control. Today, the virus is a threat not only to the countries where the outbreak has overwhelmed the capacity of national health systems, but also to the entire world. We urge our governments to mobilise all possible resources to assist West Africa in controlling this horrific epidemic.” They called for support in terms of trained HCWs from public health care systems; technical and infrastructural support in terms of field laboratories, epidemiological and microbiological surveillance resources, diagnostic equipment, and mobile communications software and technology; medical supplies such as PPE and disinfectants needed by HCWs at the treatment units; and transport and logistics.
In response to the growing epidemic that could acquire pandemic proportions if not controlled in the next few months, the first-ever U.N. emergency public health mission, the U.N. Mission for Ebola Emergency Response (UNMEER), has been established. The mission’s strategic priorities are to halt the spread of the disease, treat infected patients, ensure essential services, preserve stability and prevent the spread of EVD to countries unaffected so far. It has drawn up a comprehensive 90-day plan to reverse the outbreak trend whose objectives include acquiring capacity to isolate at least 70 per cent of the EVD cases and safely bury at least 70 per cent of the patients who die from EVD by December 1. The ultimate goal is to achieve 100 per cent in both these aspects by January 1, 2015.
Given the highly resource-strapped situation that the WHO finds itself in, with slashed budgets and staff reductions, because of member-countries’ failure in meeting their obligatory donations to the WHO, its role in achieving these targets can, unfortunately, be rendered marginal. The WHO requires $260 million to meet the objectives of its response to the outbreak. To date, it has received only 49 per cent of those funds, while 15 per cent of the funds have been pledged, leaving a deficit of 36 per cent.
In its comprehensive report of September 16 on the needs and requirements for tackling the Ebola outbreak in all the three countries, the U.N. Office for the Coordination of Humanitarian Affairs (OCHA) placed an estimate of $988 million—$473.3 million for Liberia, $220.5 million for Sierra Leone and $194.2 million for Guinea. As on November 5, only $587 million, or 59.4 per cent, has been received against the OCHA’s estimate.
In addition to this, on September 5, U.N. Secretary-General Ban Ki-moon appealed to the international community for a $1 billion Multi-Partner Trust Fund (MPTF) to be set up to enable a rapid and flexible pool fund. So far, a total of $119 million has been pledged and only $60.6 million has been committed. Since the Secretary-General’s appeal, countries have been competing in their pledges of donations, equipment and human resources. But it has come late in the day, when the horses have already bolted from the barn. Is the rate at which donations are flowing in enough to beat Ebola? The epidemic seems to have already far outpaced the international response.
